Dan Stevens, who plays Matthew Crawley in Downton Abbey, declines to sign up
for a fourth series of the popular ITV costume drama.

Viewers of Downton Abbey wept after Lady Sybil was killed off in last week’s episode. Now, however, they must brace themselves for an even more shocking departure.

Mandrake hears that Dan Stevens, who plays Matthew Crawley, the heir to the Earl of Grantham and the saviour of the estate’s finances, has declined to sign up for a fourth series of the hugely popular costume drama.

“He wants to pursue other career opportunities, particularly in America,” I am told.

His departure would be a headache for Julian Fellowes, the programme’s creator, who put Crawley’s on-off romance with Lady Mary, played by Michelle Dockery, at the heart of the show’s plot.

Crawley’s proposal to the eldest daughter of the earl won Downton Abbey’s highest-ever ratings when it was the climax of the Christmas Day special last year.

Stevens, 29, who was one of judges of this year’s Man Booker Prize, said last month that he had expected to be in the series, which was first broadcast in 2010, for no more than three years.

“I suppose, I do slightly miss the sense of an ending,” he said. “We get two scripts at a time and you’re never quite sure where the story is going.

"I mean, one minute I’m in a wheelchair and then the next minute I’m out of it – there are some quite challenging twists and turns. If you do a play or a film, at least you know whether your character lives or dies, or who he falls in love with. But with Downton …”